Genes for Speed

Abstract

![Figure][1] CREDIT: BRENDA FITZSIMONS/ THE IRISH TIMES Thoroughbred horse owners now have a new tool to predict how their nags will perform on the track. Last week at the Irish Thoroughbred Breeders' Association Expo in County Kildare, a new company called Equinome rolled out a €1000 DNA test of a muscle factor derived from the Horse Genome Project. Muscle growth is governed by myostatin, a protein that determines whether an animal has compact muscles tuned for rapid sprints or a leaner body suited for endurance. Company co-founder Emmeline Hill, left, a genetics researcher at University College Dublin, and colleagues reported last month in PLoS ONE that horses with two copies of the myostatin-suppressing C variant of the gene were more likely to win short races up to 6.5 furlongs (1.3 kilometers), whereas horses with two T variants did better in races up to 13.5 furlongs. Horse Genome Project coordinator Ernest Bailey of the University of Kentucky, Lexington, notes that breeders have adopted genetic tests for paternity, coat color, and diseases but that performance prediction is new ground. Hill says breeders have been asking about genes for temperament. That's not yet in the offing, she says, but “we're investigating gene associations with [other] parameters, such as aerobic capacity.” [1]: pending:yes